Attachment harness for a breathing mask



FIG. 1 is a left, quarter perspective view of an attachment harness for a breathing mask showing my new design;

FIG. 2 is a right, rear quarter perspective view thereof; and,

FIG. 3 is a perspective view thereof, shown in open condition.

The broken line showing of the breathing mask is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for an attachment harness for a breathing mask, as shown and described. 